BoilerFaultCodesYour boiler has lost its connection to an internal temperature sensor, which means it cannot accurately measure the heat of the water and has stopped working for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: A flashing indicator shows that an NTC sensor is broken, not connected or shorted to earth.
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the sensors that monitor water temperature. It is usually caused by a sensor failing internally due to age, or moisture causing a short circuit in the wiring. Because the boiler no longer knows how hot the water is, it shuts down immediately to prevent the system from overheating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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